JPH04119552A - Disk for recording - Google Patents

Abstract

PURPOSE:To prevent centering from being missed by forming a a circular arc shaped contact part with a rotary shaft for the positioning side of a rotary shaft inserting hole and providing a circular arc shaped part having a contact on the outside rather than the midpoint. CONSTITUTION:Circular arc shaped parts 10 and 11 are formed at positioning sides 6a and 6b and on the outside of a midpoint 10a of the circular arc shaped part 10, however, the circular arc shaped part 10 is formed so that a contact P can be positioned. Therefore, since an angle theta formed by lines/dropping from a central point O1 of a rotary shaft 8 to respective contacts P and P is larger than 90 deg., an area surrounded with this angle theta is wider than the conventional area. Thus, since the direction of the reaction of force operated onto a hub can be settled within this area, the hub is moved and centering can be prevented from being missed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording disk, and more particularly to an improvement of its hub.

[Conventional technology]

FIG. 3 shows a plan view of a conventional floppy disk cassette.

In the figure, 1 is a cassette shell, 2 is a window that communicates with the front and back sides, 3 is a floppy disk composed of a magnetic sheet 4 and a hub 5, 6 is a rotating shaft insertion hole formed in the center of the hub 5, and 7 is a rotating shaft. This is a drive bottle insertion hole provided at a position offset from the insertion hole 6.

FIG. 4 is an explanatory diagram showing the force that acts when the hub rotates,
8 and 9 are the rotating shaft and drive pin on the recording/reproducing device side, F
1 indicates the force and direction exerted by the drive pin 9, and F2 indicates the force and direction exerted by the rotating shaft 8, respectively.

By the way, when the positioning side 6a6b of the rotating shaft insertion hole 6 is linear, the contact with the rotating shaft 8 is almost a point contact. As a result of the concentrated load, the hub 5 and rotating shaft 8 wear out against each other due to repeated attachment to the recording/reproducing apparatus, resulting in relative displacement of the recording disk within the apparatus.

As a result, there were reliability problems such as off-track.

Therefore, as shown in FIG. 5, in order to increase the contact area with the rotating shaft 8, arc-shaped portions 10.
Techniques have already been proposed to eliminate the above-mentioned drawbacks.

[Problem to be solved by the invention]

However, in the conventional example shown in FIG. 5, the contact point PP between the rotating shaft 8 and each arcuate portion 10.11 is at the center point of the circular arc, and the central angle θ formed by the rotating shaft center point 02 PP is 90.
It has become a degree. Therefore, when the hub 5 rotates, the direction of the disturbance force such as the disk rotational driving force, the frictional force of the magnetic head, the lifter, etc. may deviate from the range of the central angle θ. If this happens, the rotating shaft 8 and the arcuate portion 10.11 may come out of contact (as shown by the dotted chain line in the figure), resulting in off-track.

This invention eliminates the disadvantage of off-track that the conventional products had, and has excellent chucking stability.
The objective is to provide highly compatible and reliable recording discs.

[Means for Solving the Problem] The above object is to provide a recording medium comprising a hub having a rotation shaft insertion hole in the center for inserting a rotation shaft of a recording/reproducing device, and a recording medium fixed to the outer circumference of the hub. This is achieved by forming the contact portion of the positioning side of the rotary shaft insertion hole with the rotary shaft in an arc shape in the disk for use with the rotating shaft, and providing at least one arc-shaped portion having a contact point outside the midpoint. .

[Effect]

By expanding the area surrounded by the rotation axis center and the central angle of the two contact points with the positioning side by more than 90 degrees, the direction of the reaction force of the resultant force of various forces acting on the hub is kept within that area. ing.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Note that parts similar to those in the conventional example are given the same reference numerals and redundant explanations will be omitted.

FIG. 1 is an explanatory diagram showing the contact point between the rotating shaft and the hub, and FIG. 2 is an explanatory diagram showing the formation position of the circular arc portion.

As shown in FIG. 1, arcuate portions 10.11 are formed on the positioning sides 6a and 6b, and the arcuate portions are arranged so that the contact point P is located outside the midpoint 10a of the arcuate portion 10. 10
is formed.

That is, in this case, as shown in FIG. 2, the center 02 of the circle forming the arcuate portion 10 is offset from the center 03 of the arcuate portion II.

Returning to FIG. 1 again, the angle θ formed by the line drawn from the center point 01 of the rotating shaft 8 to each contact point P, P, in other words, the angle θ at which the perpendicular to each contact point P, P changes is 90 degrees. This angle θ is larger (approximately 95 degrees to 110 degrees), so this angle θ
The area surrounded by is wider than the conventional example. Therefore, since the direction of the reaction force acting on the hub 5 can be contained within this region, it is possible to eliminate the drawback that the hub 5 moves and is not centered.

〔Effect of the invention〕

As explained above, in the present invention, the center line of at least one of the circular arc portions does not pass through the center of the rotating shaft, and the central angle formed by the two contact points with the center of the rotating shaft is 90°. Since it is set to a value greater than 1°, it is possible to avoid misalignment between the rotating shaft and the positioning side (arc-shaped portion thereof) on the inner periphery of the hub, thereby increasing centering accuracy.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the contact point between the rotating shaft and the hub, Fig. 2 is an explanatory diagram showing the formation position of the circular arc portion, Fig. 3 is a plan view of a conventional floppy disk cassette, and Fig. 4 is an explanatory diagram showing the contact point between the rotating shaft and the hub. FIG. 5 is an explanatory diagram showing the force that acts when the hub rotates, and FIG. 5 is an explanatory diagram showing the contact points between the rotating shaft and the hub according to a conventional example. 5... Hough, 6... Rotating shaft insertion hole, 6a, 6b...
・Positioning side, 8...Rotation axis, 10.11...Circular arc portion, P...Contact point. Figure Figure Figure Figure

Claims (1)

[Claims] In a recording disk consisting of a hub having a rotary shaft insertion hole in the center for inserting a rotary shaft of a recording/reproducing device, and a recording medium fixed to the outer periphery of the hub, the positioning side of the rotary shaft insertion hole is A recording disk characterized in that a contact portion with a rotating shaft is formed in an arc shape, and at least one arc portion has a contact point outside the center point.